Help, Ducklings left on their own tonite!

Hi, Mumma duck has decided to have a break from the littlies but at Night??? she is sitting 2 feet away from them and they are all huddled in their shelter cheeping because they want her to keep them warm . we have just come into spring.
The night is overcast with cloud cover and it is very mild with the first rain for 3 weeks expected tonite.
This is the first time she has left them to huddle up without her. Has anyone seen this, i expect it must be normal?
Im tempted to grab some long extension cords and plug in a red globe, but that will stress everyone out, the duck will attack me and they will all be unsettled.
Any thoughts on this! has anyone used a brooder lamp for added warmth when a mumma duck is 1/2 present?
perhaps she would like it also. but as I said i dont wish to do this unless really necessary, otherwise ill hook it up in the morning when I can see without a torch!
Its also a full moon here, perhaps she is on a moon high!

Hmmmm, I dont know. My momma duck didnt leave the babes ever! How old are the babes again?? Maybe she just wants some alone time? I think they should be ok....if they want to get warm, they will go over to momma...

Ok ive just gone out there, its now 11.35pm she had 3 under her and the rest were huddled on each other. I hope they dont get too cold, im not sure if they have enough down on them to survive. Can anyone help please?

Im worried that if I go in there mumma duck will kill me!!!
No, she will make a huge racket, wake up the neighbours and unsettle the ducklings. Im waiting up tonite to see if a duck breeder has seen this happen!!its now 12.34am.
Thanks bayouchica

Ok, looks like ive got some work to do!! ill have to search the house for long cords then tape over the joins to make them waterproof and try to get a light in the cupboard that they are under. If it was daytime I could make some noise and drill a hole in the back of the cupboard for the lampbase. I just went out again and she had moved to her original nest but had only a few under her.
The others were huddled in a heap beside her. She has 14 and watching her today she did look uncomfortable with her wings stretched out over them.
Do you think she has too many to do this on her own?
If I think she is going to let the toughest only survive, i would definately take them in and hand rear them, which would be nicer for me!!!as i would get much tamer ducks.
Boy am i in a spot.